I'm with Bad Mojo . . . . the G30 is a great carry weapon. The G21 is too big. I've been conceal carrying for a long time. played with a lot of holsters . . a shoulder holster is a waste of time and money. Every serious instructor will tell you that. Shoulder holster were designed for people who reasonably know when they are going to draw there weapon . . . as an ACTION, not a REACTION.
Hear me out for a minute. . . . or two. . or three!
I have 4 Kimber 1911s. three of them in the 4" Pro-carry (commander size) I have a Sig P228 and a P229 Elite - arguably one of the best, if not the best, combat handgun ever. I have a Glock G30, G19, G26.
I used to carry the Sigs exclusively. The thought was they are thinner lighter, and have more capacity. With a 147g +P round you can kill just about any bad guy.
When I got real serious about the whole idea behind conceal carry or open carry - I do both. I decided that the 45ACP best suited me. I am more concerned about stopping power than capacity.
I started carrying my Kimbers while at home and in public, in condition 1, or "****ed & locked" I also carry 1 or 2 additional mags depending on my moods.
On a dare, I bought the G30 . . . .remember I'm a diehard Sig guy. I loved the G30 so much I decided to start carrying it. I carry it all of the time. I do still carry my 1911s more than 1/2 the time I carry, but if I want something quick an simple, won't snag my clothes, and has 45ACP 230g +P I go for the G30. There is nothing simpler than a Glock. That's why everybody that makes a handgun these days is copying it. Including Springfield.
I only pack the Sigs when I'm wearing a tight or form fitting outfit, like a tailored suit. The Sigs are also the firearms that are always loaded at home, always placed where I may need them, where my wife may need them. I can guarantee that they will fire, fire true and straight every single time.
I carry the G26 as a back-up in an ankle holster when I'm in the mood for it - rarely, but for a sub-compact its a smooth shooter. I bought a Gen 4 G19 because its cool! never carried it.
75% of the time I carry IWB (inside waist band) it may feel weird at first, but with the right holster you get used to it very quickly. I have several models and types of IWB holsters, but I started carrying exclusively with the Comp-Tac MTAC holster. They are not the cheapest, but they are the best in my opinion. There is a lot of things you can do with it. Although I have 4 of them, you can purchase a holster, and then multiple skins for each pistol you would want to carry. They also by far!!!! . . . have the best mag holsters!! I don't work for them, don't "promote" them, hell I don't even know them, other than their product is top notch!
Don't waste your time with the Cross-Breed or Galco copy-cats. The metal clips will tear your clothes, scratch your furniture, ruin your belts, and cut you leather seats!
If you prefer an OWB holster and you live someplace where you can even get in trouble if someone can see something that looks like a gun under your shirt, I'd suggest one of the traditional leather holster that have a high ride to them. I have Galco Concealment holsters for all of my carry weapons. They stick close to your body, ride high on your waist, and don't have a strap to worry about fumbling with when you need it.
Most of the time when I do open carry or use an OWB I use a Comp-Tac Cant holster or a SERPA. If I need to keep it tight, up and out of view I switch to the Galco.
In short!!!!! . . . If you don't have a ton of experience start packing your G30, its simple, and out of the box one of the best shooting pistols available . . . send the shoulder holster to the Goodwill, at minimum get an MTAC IWB. at first your waist may feel a little tight. get used to it. It is by far the best way to conceal, if concealed is your intent. Don't waist your money or your life for that matter on a pocket pistol. those things were meant to be back ups. they are better than nothing, but also give you a very false sense of security. If you must buy a 9mm get a G19 or a G26, not because they're the best, but because you are already familiar with it.
3 months ago I bought a new pistol for my brother who has only owned one pistol, a Chinese Russian copy . . .need I say more!! I asked my old school gunny sarge friend at the counter who is a diehard Springfield guy. . . . which is the better gun all around for a novice to reasonably experienced shooter, the Gen 4 Glock or the XD? We talked about a lot of things . . . In the end he made the choice for me, I bought two G19s that day. Need a good solid entry level no nonsense gun, go with the XD. If you can afford a little more, want something that is proven to be a more solid player, trust your life with it for the next 30 years, get a Glock.
There's my 50 cents worth!